Magnetoresistive random access memory (MRAM) is a non-volatile random access memory which gains popularity in recent years as potential replacement for dynamic random access memory (DRAM), static random access memory (SRAM) and flash. MRAM, for example, includes magnetic tunnel junction (MTJ) element which uses magnetic polarization to store information. For example, READ and WRITE operations of the MRAM device rely on the MTJ element. However, magnetic interferences can be a problem for MRAM devices. For instance, MTJ functions can be affected by an external magnetic field. The external magnetic field may come from sources of magnetic flux such as power lines, bar magnets, or the earth. The external magnetic fields not only distort magnetic signals within the MTJ memory, but also induce changes on electrical signals of the circuits. READ and WRITE operations in MRAM devices are inevitably affected by external magnetic fields. These cause reliability issues in MRAM devices. As technology advances, there is also a desire to integrate and vertically stack MRAM chips with other suitable chips, including but not limited to logic chip, in a single package to form a 3-dimensional (3D) integrated circuit (IC) package.
Accordingly, there is a need to provide reliable and cost effective wafer-level processing which provides for magnetic shielding to protect the MRAM chip from external magnetic fields and stacking of MRAM chips with other chips in a vertical manner.